FAQ-What the hell is this white empty cell??

This two month I received more than 20 reports about a strange error.

The report said there are some white empty cells in the mosaic image. 
And I received some sample. like the following one:

After look at the design, I understand what happend:
They did not load enough cell photos. 
To create a good photomosaic, you should load more than 20 photos.
In the sample project, they only load 7 to 10 photos. It’s is not enough.

And there is a very simple solution:
Load more photos.

Look, here are samples I load 5 more photos, and 10 more photos,
The white empty cells are removed now.